Figure 6.

Plant natriuretic peptides (PNPs) alleviate hypersensitive response (HR) symptoms in the interaction of Arabidopsis thaliana with Xanthomonas axonopodis pv. vesicatoria (Xav). Four‐week‐old plants were flood inoculated with Xav. (a) Representative images of plants at 2 days post‐inoculation (dpi). Col‐0 and Col‐0 EV showed similar symptoms to Col‐0 rdr6 EV (rdr6 EV) and, because of the large amount of data, were not included. EV, empty vector. (b) 3,3′‐Diaminobenzidine (DAB) detection of H₂O₂ accumulation in leaves inoculated with Xav at 1 dpi. Representative photographs of DAB‐stained leaves are shown. (c) Quantification of DAB staining from the microscopic images as described in Experimental procedures. The means were calculated from five photographs from three independent experiments for each line. Error bars indicate standard deviations. Mock indicates treatment with sterile water and Silwett L‐77 0.025% (v/v). nd, not detected. The data were analysed by analysis of variance (ANOVA) followed by Tukey's test. Bars with different letters are significantly different (P < 0.05). (d) Ion leakage quantification at 18 h post‐inoculation (hpi). Values represent an average of four plants assayed for each line and the experiment was repeated three times. Error bars are standard deviations. The data were analysed by ANOVA followed by Tukey's test. Bars with different letters are significantly different (P < 0.05).